What is Crab Trap?
1.
Someone so slutty they seem to bait and trap crabs (and other STDs).
That girl is a total crab trap.
See
2.
A practical joke designed for one-person public restrooms. You bring a rubber glove as it will get messy, making sure you ate some spicy mexican food or other natural laxative beforehand. After properly applying the glove on your hand, shit in the toilet and pick it up smearing it on the door handle inside the bathroom, sink faucet, toilet paper, and paper towel dispenser. Be careful to keep the toilet clean as if you leave it dirty the prey will not take the bait of a clean, unharmed toilet. Doing this will ensure that the person can't get out of the restroom without touching shit in some way, unless he calls for help.
Oh shit! I just got hit with a crab trap! It's just like the method those people use on discovery channel.
See